Can't log in

Hey, I've recently been having this issue logging into the game. Here's what happens:

After I enter my login information, the game does its "Login status - logging in..." thing, which then usually brings us to the main lobby of League of Legends.

However, instead of bringing me to the lobby, it simply leaves me at the "login status - logging in..." Loading screen endlessly.

Sometimes it goes on, and on, and sometimes it gives me a message saying "An unexpected error has occured".

I've repaired the client AND re-installed League of Legends.

Any guidance would be appreciated!